Insert the Pins into hole directly and it can locking the bolts fast and effectively. It gives fast and secure hold for bolts,and remove. Suitable for machinery,tractors,farm equipment,engines,trucks,car and garden equipment. Make of Carbon steel galvanized,rusts and resistant,Enduring and not easy to break. Fast,Safe and effective locking bolts,uniform force,not easy to slip,will not fall down,easy installation and disassembly.